Showing papers by "Hisashi Yamamoto published in 1997"
TL;DR: Sterically hindered aluminium aryloxides have been developed as designer Lewis acid catalysts for stereo-, regio-and chemo-selective reactions as discussed by the authors, and these aluminium reagents coordinate strongly with various======oxygen-containing substrates, and this coordination is affected by the======consuming environment of their ligands.
91 citations
51 citations
22 citations
TL;DR: Conjugate 1,6-addition of silyllithium reagents to aromatic carbonyl reagents gave allyl-silanes as discussed by the authors, which were then used in the presence of the carbonyls protector aluminiumーテtris(2.6-diphenylphenoxide) (ATPH).
20 citations
14 citations
TL;DR: The regioselective coupling reaction of epoxides with allylic barium reagents was achieved and all reactions resulted in high yields with remarkable α-selectivities.
Abstract: The regioselective coupling reaction of epoxides with allylic barium reagents was achieved. All reactions resulted in high yields with remarkable α-selectivities. 2-Propynylbarium reagent afforded exclusively the corresponding acetylenic alcohol.
9 citations
TL;DR: In this article, the activator ability of sterically crowded aryloxide compounds of aluminum to aluminum-porphyrin catalyzed (Inoue) polymerization of methylmethacrylate (MMA) was investigated.
9 citations
TL;DR: In this paper, the addition of lithium enolates derived from ketones to a variety of α,β-unsaturated ketones was realized in the presence of aluminum tris(2,6-diphenylphenoxide) (ATPH).
Abstract: Michael addition of lithium enolates derived from ketones to a variety of α,β-unsaturated ketones was realized in the presence of aluminum tris(2,6-diphenylphenoxide) (ATPH). In this reaction, ATPH can be used as a carbonyl protector of α,β-unsaturated carbonyl substrates upon complexation, which facilitates the regioselective 1,4-addition of lithium enolates to Michael acceptors. Similarly, dianions of β-dicarbonyl compounds undergo Michael addition smoothly using ATPH as an effective promoter of the reaction. Subsequent regioselective, intramolecular aldol condensation was also demonstrated, leading to bicyclic carbon ring systems. Such systems are difficult to obtain by the Robinson annulation usually performed in protic media.
8 citations
7 citations
Journal Article•
TL;DR: In this article, the regioselective coupling reaction of epoxides with allylic barium reagents was achieved, and all reactions resulted in high yields with remarkable α-selectivities.
Abstract: The regioselective coupling reaction of epoxides with allylic barium reagents was achieved. All reactions resulted in high yields with remarkable α-selectivities. 2-Propynylbarium reagent afforded exclusively the corresponding acetylenic alcohol.
TL;DR: In this article, the addition of lithium enolates derived from ketones to a variety of α,β-unsaturated ketones was realized in the presence of aluminum tris(2,6-diphenylphenoxide) (ATPH).
Abstract: Michael addition of lithium enolates derived from ketones to a variety of α,β-unsaturated ketones was realized in the presence of aluminum tris(2,6-diphenylphenoxide) (ATPH). In this reaction, ATPH can be used as a carbonyl protector of α,β-unsaturated carbonyl substrates upon complexation, which facilitates the regioselective 1,4-addition of lithium enolates to Michael acceptors. Similarly, dianions of β-dicarbonyl compounds undergo Michael addition smoothly using ATPH as an effective promoter of the reaction. Subsequent regioselective, intramolecular aldol condensation was also demonstrated, leading to bicyclic carbon ring systems. Such systems are difficult to obtain by the Robinson annulation usually performed in protic media.